Rock paper scissor

RPSGame.hs

import Text.Read (readMaybe)
import System.Random (randomRIO)

data Move = Rock | Paper | Scissor deriving(Eq, Read, Show, Enum)
data Result = Victory | Defeat | Draw deriving(Show)

play Rock Scissor = Victory
play Paper Rock = Victory
play Scissor Paper = Victory
play a b
    |a==b = Draw
    |otherwise = Defeat
	
ai = do 
    i <- randomRIO (0, 2)
    return $ [Rock ..] !! i
    
getInput = do
    input <- fmap readMaybe getLine
    case input of
        Just x -> return x
        Nothing -> do
            putStrLn "Please chose a valid value"
            getInput
	
main = do
    putStrLn "Rock Paper Scissor?"
    choice <- getInput
    aichoice <- ai
    putStrLn $ "The computer selected " ++ show aichoice
    print $ play choice aichoice